Maria isn't scary at all. In the first 3 Episodes Battler should have freaked out 3 times because of Maria and one time after reading the epitaph.
1. Maria scares him with a story about Beatrice on the beach before giving the talisman.
2. The scene when Battler gets back to the guest house is comepletly wrong. He doesn't tell her that people died. He accidently mentions it Jessica warns him, and Maria goes to Battler in a Rena manner;" Who died?Their faces were torn off, they were just chosen by .... as ...... Be lucky you had a talisman that protected you or else you would have died *kihihihihihi*"
3. They Butler tries to figure out what was the symbol written in blood before they found the corpses and Maria interrupts him show that she knows about the symbol of the sun, meaning of sacrifice etc. and starts to laugh again." instead of talking to him in a cam manner.

The main idea Umineko ist based on the idea of Tatarigorishi-hen.
Whether Magic exists or it doesn't.

Even without the first anwer arc beeing released I guess, that most of the characters aren't magic but the island is.

The biggest flaw is the censorship of the anime because of the hatched murdering, since it doesn't leave much room for speculation.

My theory is that Hypnotizing characters is the key of the series.

So here is my theory.

Beatrice and Maria meeting:

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I guess it was Shannon since she thinks of herself as furniture like Kanon(Deen screwed up), or it was Beatrice who later hided in the big mansion

The first Night+Second Night.

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My Guess is that only 4 people died, Ghoda, Shannon, Klaus and Rosa because only half of their Face got smashed/disfigued by acid/torn apart. Kyries face is completely destroyed so you can't identify her and Rudolfs "corpse" is beheaded even harder to identify.
The objective was only to kill Klaus and Rosa, Ghoda and Shannon were just in way(in the novel you get a desription that Shannon looks in the sky after George left and putting the ring over her finger and suddenly gets shocked by something(blood/gore screen).
Eva and her husband should have been the suspects, but they found out that neither Natushi nor the Butlers had something to do with the killing and they ironically got killed on the 2nd night.

I don't know how hard the censorship will be but in the second and third arc you get some really bloody/images ot even full of gore.

For example you get explained why Maria didn't start to cry after

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she leared of the death her mother

because some time ago, Rosa created a stuffed animal for Maria and Maria gave him a name and it was her only friend, she imagined? him as young boy.
After Maria got 9, Rosa snaps out and "kills" that stuffed animal by smashing it against a wall many times ripping the throat and stomach etc. with the same text after Maria said "ummmmn" many times in the gardenand Maria only sees her friend getting killed by her mother in a brutal bloody manner.

Spoiler Alert! Click to show or hide

Beatrice appears and Maria want her to revive her friend(repair the stuffed animal in reality?) but Beatrice says she can't because it was Rosa's creation and only she can revive him and her magic isn't powerfull enough(rather she sux in sewing) and her friends soul will always be alive in her till she stops believing in him.
After that day Maria wanted to learn magic

This hint clarify that much stuff isn't magic but there is stuff you can't explain yet.

I started watching this cause it seemed interesting. As i kept watching it, it became interesting on who could be doing the killings, then it was just plain amazement on the rules of the game. I mean, he is either very smart or just plain stubborn to a point that I thought Beatrice would just kill him off completely. Still, i just found it an interesting logic anime. While one fought to prove magic, when the other firmly denied it even when it stared him right in the face. It was just too too wow.